CH-Aktivierungsreaktionen an substituierten Zirconocenkomplexen und deren Verwendung in der katalytischen Ethylenpolymerisation

Zirconocene dichloride complexes with substituents containing aliphatic end groups at the aromatic ligands react with two equivalents of n-butyllithium to give metallacyclic zirconocene complexes via aliphatic CH-activation reactions. As well as ω-alkenyl substituted zirconocene dichloride complexes with terminal aliphatic groups as zirconocene dichloride complexes with purely aliphatic substituents are suitable for the synthesis of such metallacycles. In combination with methylalumoxane (MAO), these metallacycles are excellent catalysts for ethylene polymerization. Their activities can be three and a half times higher than the activities of the corresponding zirconocene dichloride educts. The catalyst 25/MAO is able to produce 2640 kg PE g−1 Zr h (60 °C, pentane solution, 10 bar ethylene pressure).